Re: [ATMSAR] Request for review - update #1

[Grzegorz Kulewski <kangur@polcom.net>]

On Sun, 4 Sep 2005, Alistair John Strachan wrote:

> On Sunday 04 September 2005 12:05, Giampaolo Tomassoni wrote:
>> Dears,
>>
>> thanks to Jiri Slaby who found a bug in the AAL0 handling of the ATMSAR
>> module.
>>
>> I attach a fixed version of the atmsar patch as a diff against the 2.6.13
>> kernel tree.
>>
> [snip]
>
> Just out of curiosity, is there ANY reason why this has to be done in the
> kernel? The PPPoATM module for pppd implements (via linux-atm) a completely
> userspace ATM decoder.. if anything, now redundant ATM stack code should be
> REMOVED from Linux!
>
> Most distributions (to my knowledge) supporting the speedtouch modem do so
> using the method prescribed on speedtouch.sf.net; an entirely userspace
> procedure. pppd does all the ATM magic.
>
> Does this have real-world applications beyond the Speedtouch DSL modems? If
> not, I propose adding this code to linux-atm, not the kernel, since most
> users of USB speedtouch DSL modems will not be using the kernel's ATM.

I am using SpeedTouch 330 modem with kernel driver (on Gentoo).

The instalation is currently (with firmware loader instead of modem_run) 
very simple: USE="atm" emerge ppp, download firmware and place it in 
/lib/firmware, compile the kernel with speedtch support.

I tried to use userspace driver some time ago but it wasn't working for me 
so I gave up. I was using modem_run with kernel driver for long time to 
load the firmware but there were many problems with it too (nearly every 
kernel or modem_run upgrade was breaking something, modem_run was hanging 
in D state in most unapropriate moments and so on).

Now I am using pure kernel driver and firmware loader and it works 100% 
ok. There were no problems with it for long time. And I don't even want to 
look at this userspace driver again.

Since Linux newer was (or is going to be) userspace-driver OS, maybe we 
should leave it that way...


Grzegorz Kulewski